(19)

(11)

EP 0 478 614 A1

(12)

(43) Date of publication: 08.04.1992 Bulletin 1992/15 (21) Application number: 90909153.0 (22) Date of filing: 21.06.1990

(51) International Patent Classification (IPC):  G06F 3/ 033( . ) H03K 17/ 96( . ) G06F 3/ 038( . ) (86) International application number: PCT/GB1990/000959 (87) International publication number: WO 1990/016045 (27.12.1990 Gazette 1990/29)

(84) Designated Contracting States: DE ES FR GB IT NL SE (30) Priority: 21.06.1989 GB 19890014235 15.09.1989 GB 19890020999 (71) Applicant: TAIT, David Adams Gilmour Dorking, Surrey RH4 3HX (GB)	(72) Inventor: TAIT, David Adams Gilmour Dorking, Surrey RH4 3HX (GB) (74) Representative: Lightfoot, Robert Oscar, et al  Raworth, Moss & Cook 36 Sydenham Road Croydon Surrey, CR0 2EF Croydon Surrey, CR0 2EF (GB)